Abstract: The invention is an improvement in a lightweight carbon-carbon composite piston, the improvement comprehending the use of near-net shape knitted or warp-interlock pre-forms to improve the structural qualitites of the piston. In its preferred embodiment, a one piece, tubular, closed-ended, knitted pre-form (a sock) of carbon fibers (11) embedded within the matrix of the piston structure forms the crown (12), side wall (15), skirt (16) and inner surface (18) of the piston, and wrap-interlock pre-forms strengthen the piston crown and wrist pin bosses.

Abstract: A plastic pneumatic cylinder has a cylinder housing, a piston within the housing, and a rod on which the piston is mounted. The cylinder is molded of a plastic synthetic resin and has a cylindrical bore of a predetermined diameter. The piston is molded in one piece from plastic synthetic resin, such as Delrin, in the form of a generally cylindrical body and a generally cylindrical sealing lip surronding and spaced radially from the body to seal slidably against the bore. The lip is flared out somewhat to have an edge that is of a greater diameter than the bore. The piston can be formed in single-acting or double-acting configurations. A conical return spring can be employed.

Abstract: A piston slidably inserted in the cylinder of a gas pump, said cylinder having a cylinder head and an outlet valve located near the cylinder head. The piston comprises a cylindrical piston body and a wear-reducing sheet wound one time around the piston body. The opposing edges of the wear-reducing sheet are cut stepwise, such that at least two gaps are formed between the edges, which are set apart from each other for a predetermined distance in the circumferential direction of the piston body, and such that no gap portion is formed between the edges, which connects the two gaps and extends substantially in the circumferential direction of the piston body.

Abstract: In a piston-cylinder assembly for hydraulic brake systems of automotive vehicles, the piston is at least partially composed of ceramics. A hydraulic seal is interposed between the piston and the cylinder. To simplify the assembly while allowing comparatively great tolerances, the seal is fitted at the end of the piston that is adapted to be mounted close to a pressure chamber within the system. The seal is provided with radially-extending projections which cause the piston to spring back by a roll-back effect.

Abstract: An apparatus for providing a gas phase film lubrication between a reciprocal piston and a cylinder of an uncooled oilless internal combustion engine; the piston is effective to drive a rotary crankshaft in response to an expanding gas charge. The apparatus comprises: (a) means connecting the crankshaft to said piston for transferring reciprocal thrust into rotary thrust, such means aligning the piston concentrically within the cylinder wall to limit the imposition of side loads on said piston (i.e., less than 80 psi); (b) interfacing walls on the piston and cylinder (i) sized to provide a predetermined annular gap therebetween at ambient conditions that has a radial dimension in the range of 0.001.+-.0.

Abstract: In order to achieve a positioning close to a combustion chamber of a swivelling axis between a connecting rod and a piston, a curved surface region facing a piston head of a tensioned band which is subjected only to tractive stress and is looped around a connecting rod shank, forms also the pressure transmitting component of a pivot bearing in that it rests directly on a bearing surface on the piston head.

Abstract: A piston assembly including a plastic piston defining a socket at its rear face and a metallic annular insert member positioned within the socket and receiving the piston rod of the piston assembly in acting to increase the effective area over which the loading from the piston rod is applied to the plastic piston so as to allow the plastic piston to be used in environments where it might otherwise fail due to the high stress loading. The annular insert also includes prongs struck from the main body portion of the insert member and coacting with an annular shoulder on the piston rod to preclude axial withdrawal of the piston rod from the piston and further includes an annular flange portion which acts to facilitate positioning of the insert member in the socket in the piston and further acts to define the fully retracted or extended position of the piston in coaction with a snap ring on the inner periphery of the associated cylinder.

Abstract: A syringe which has a barrel, an annular elongate liner that is constrained by the barrel and a plunger head. The liner and the plunger head are made of a fluorinated polymer material, such as Teflon. The plunger head has first and second sealing surfaces and a portion of reduced diameter between them. The first sealing surface provides a fluid seal whereby fluid is drawn into and forced out of the syringe. The second sealing surface forms a particle trap with the inner bore of the liner to keep any fluorinated polymer particles from escaping from the portion of reduced diameter between the first and second sealing surfaces.

Abstract: A swash plate pump includes a housing and cylinders arranged in a circular pattern around the drive shaft. Piston rods are pivotally connected at one end to the swash plate and mechanism surrounding the drive shaft and axially slidable along it controls the angle of the swash plate. The opposite end of each piston rods is fixed to a piston. In one embodiment, each piston rod is locally reduced in cross-sectional area adjacent its piston to compensate for disparity in arcuate motions of the opposite ends of the piston rod and in another embodiment, the cylinders are mounted in ball joints in the housing to compensate the disparity. One end of the housing may be formed as a manifold and double seals are provided between the compression side and the drive side of the pump.

Abstract: Light alloy articles comprising a body of light alloy having a composite fiber/light alloy layer, a sprayed heat-resistant alloy layer, and a sprayed ceramic base layer formed on the body in this sequence exhibit improved heat resistance and insulation and are very useful in the manufacture of internal combustion engine pistons. A method for producing such a coated light alloy article by spraying is also provided.

Abstract: A reciprocatory piston and cylinder machine particularly suitable for use as a vacuum pump includes a cylinder (17), a cylindrical piston (16) relatively slidably reciprocable within the cylinder (17), and means for substantially sealing the annular space between the piston (16) and cylinder (17) in lieu of oil or other liquid lubricant. The sealing means comprises a sleeve (102) of a low-friction material disposed under circumferential tension, and preferably also under longitudinal tension, on the cylindrical surface of the piston (16). Also disclosed is a reciprocatory piston and cylinder machine of particular prior construction having a one-way valve (42) in an exhaust port (30) ahead of a head portion (24) of the piston (16). The arrangement is such that, as the front face of the piston head portion (24) approaches the closed cylinder end (52), the piston head portion 24 physically moves the one-way valve (42) so as to open the exhaust port (30).

Abstract: Fluid actuator includes a piston rod comprised of a wound filamentary composite structure to provide an extremely light weight, relatively low cost, envelope efficient design. Attached to the piston rod are one or more non-integral piston heads which are preloaded against one or more ramp surfaces on the exterior of said piston rod. A pair of oppositely facing ramp surfaces may be formed on the piston rod by interspersing filler means between the piston rod fiber layers. Another ramp area may be formed by providing an external groove in the piston rod which is engaged by longitudinally split support shoes that provide an attachment surface for a detachable piston head. An internal ramp may also be provided on the inner diameter of the piston rod adjacent the axial outer end thereof for mating engagement by a conically ramped exterior surface on an internal metal stud used to attach a rod end assembly to the axial outer end of the piston rod.

Abstract: An internal combustion engine includes a cylinder block, a piston and a piston ring. The cylinder block includes at least one cylinder bore which includes a cylinder bore surface. The piston is located within the cylinder bore of the cylinder block so as to be displaceable upwardly and downwardly in the longitudinal direction of the cylinder bore. The piston includes at least one annular groove which has at least one inclined surface such that a bottom of the annular groove is located lower than an outer edge of the annular groove. The piston ring includes an outer peripheral portion and an inner peripheral portion. The inner peripheral portion of the piston ring is located within the annular groove of the piston for sliding engagement with the inclined surface of the annular groove of the piston.

Abstract: A hydraulic master cylinder has a piston of cylindrical section slidably sealed within the cylinder bore. An insert is mounted on the piston and defines an axial groove for engagement of an abutment projecting laterally into the cylinder bore, and a transverse slot for retention of a lever which is adapted to engage the abutment to control the opening and closing of a breather valve.

Abstract: A pump plunger formed from a centrally bored cylinder of a preferred compound having counterbored ends provided with inwardly converging counterbore inner end limits for thermally shrinking and centering a bolt and its nut therein. One end of the bolt projects beyond the cylinder and is threadedly connected axially with a plunger mounting shaft. The cylinder is turned concentric with the mounting shaft.

Abstract: In a plate clutch, an annular cylinder chamber with a moveable annular cylinder portion is located in a transition region between a radial flange and a cylindrical external plate carrier integral with the radial flange. The position of the annular cylinder portion is fixed in the radial and axial directions relative to the external plate carrier by the flange which fixes the annular cylinder in one axial direction of the clutch axis and by means of a circlip in the other axial direction of the clutch axis. In order to improve the sealing of the working pressure chamber enclosed by the annular cylinder portion, the annular cylinder is supported in the radial directions by means of a ring seal, so that it can move and be also elastically carried on the external plate carrier.

Abstract: An aluminum torpedo piston is provided with a piston head fabricated from a etal matrix composite material composed of aluminum and silicon carbide fibers that are integrally joined by an inertial welding technique. A 23% weight of silicon carbide fibers to powdered aluminum was selected. Resistance to intense heating which would otherwise cause melting and erosion of the piston is avoided to permit longer, high speed runs.

Abstract: An injection-molded piston for an aerosol container has a face portion for contacting and exerting pressure on material to be dispensed, and a thin, flexible skirt depending axially from and circumscribing the face portion for forming an effective seal against the inside wall of the container. The outer wall of the skirt is continuous, while the circumference of the inner wall has alternating areas of constant thickness along said areas and areas of minimum thickness, the curved portions forming with the outer wall a plurality of sections, the thickness and circumferential extent of each of which decrease axially along the skirt toward its distal end. The piston includes a depending extension on the skirt which aids sealing.

Abstract: A reciprocatory piston and cylinder machine particularly suitable for use as a vacuum pump includes a cylinder (17), a cylindrical piston (16) relatively slidably reciprocable within the cylinder (17), and means for substantially sealing the annular space between the piston (16) and cylinder (17) in lieu of oil or other liquid lubricant. The sealing means comprises a sleeve (102) of a low-friction material disposed under circumferential tension, and preferably also under longitudinal tension, on the cylindrical surface of the piston (16). Also disclosed is a reciprocatory differential piston and cylinder machine of particular prior construction having a one-way valve (42) in an exhaust port (30) ahead of a head portion (24) of the piston (16). The arrangement is such that, as the front face (28) of the piston head portion (24) approaches the cylinder end face (52), the front face (28) physically moves the one-way valve (42) so as to open the exhaust port (30).

Abstract: Two concentric vertical cylinders are separated by three radial partitions. An opening at the bottom of one of the partitions connects an air cell on one side of the partition with an outlet chamber on the other side of the partition. The two other partitions form sides of an inlet chamber, which receives fluid from outside the outer cylinder. The inner cylinder has a central pumping section positioned between upper and lower valve sections. In the valve sections ports extend through the inner cylinder wall to the inlet and outlet chambers. Spring loaded valves close the ports. Tension springs extend across the inlet chamber or compression springs extend across the inner cylinder to close the inlet valves. Tension springs extend across the inner cylinder to close the outlet valves. The elastomeric valve flaps have rigid curved backing members. A piston rod extends through one end cover to move a piston in the central section.

Abstract: A metal-ceramic composite article obtained by press fitting a projection of a ceramic member into a hole formed in a metallic member has a high bonding force in the press-fitted portion and is free from separation between the ceramic member and the metallic member. The composite article exhibits high thermal resistance or wear resistance when used as a piston crown in a piston for an adiabatic engine or when used as a cam contacting surface of a tappet.

Abstract: A metal and plastic two-stage composite piston including an annular metal cup, a hollow plastic annular core bonded about the periphery of the cup, a plastic high pressure piston bonded to the interior of the cup, and a plastic low pressure piston bonded about the periphery of the core at the base of the high pressure piston in a fashion such that substantially all of the pressure loads on the pistons are carried directly by the cup and the core of the composite piston.

Abstract: A piston carries on its skirt surface a number of separate strips of a plastics material, such as a polyetheretherketone alloy, so that the strips are hydrodynamically lubricated and transmit lateral thrust from the piston to an associated cylinder or liner. The strips are just proud of the skirt surface and may be contained in recesses formed in the skirt surface.

Abstract: A piston (2) is of refractory materials, particularly for a compression-ignition engine of the type having a head (4), a skirt (6) and their mutual fastening means. According to the invention, this skirt (6) is formed entirely of a refractory material and has two semicylindrical parts (18, 20) each of which has ribs (22) and a semispherical cavity (36, 38). After assembly, the cavities form a ball joint seat for the small end of a piston rod along a plane containing the longitudinal axis (14) of the piston (2). Application is to compression-ignition engines with high efficiency.

Abstract: An integrally cast composite piston assembly is disclosed which is effective to carry a ceramic plate in an iron based cap. The assembly comprises a cylindrical piston body, preferably of aluminum, having a crown top, an annular crown side wall with an upper edge, and an annular undercut surface terminating the crown side wall. The undercut surface must make an angle with a plane extending perpendicular to the axis of the piston, the angle being substantially equal to the arc tangent of H/R where H is the median distance of the undercut surface from the plane and R is the median radius of the undercut surface from the axis of the piston.

Abstract: A fiber-reinforced lighweight alloy piston for an internal-combustion engine, comprising a piston body having a compression ring groove whose bounding surface is reinforced with alumina fibers. At least those alumina fibers positioned in the region of the annular opening of the groove has a crystalline structure of .theta./.alpha.-Al.sub.2 O.sub.3 type and a specific gravity limited to a value between 3.7 and 3.9.

Abstract: A piston for a precision dosing instrument includes a cylindrical core which may be made of glass, ceramic or metal, and a precision ground sleeve of polytetrafluorethylene disposed over the core. One end of the sleeve is closed while the core is open at both ends.

Abstract: The piston cylinder type damper comprises a cylinder connected to either member of the pair of a main body and an openable object, and a piston connected to the other member of the pair and adapted to fit into the cylinder and the piston incorporates therein a check valve adapted to allow the air in the cylinder to escape from the cylinder interior while the piston is driven into the cylinder by the movement of the openable object.

Abstract: A sealing apparatus is disclosed for a device having variable volume chambers formed by the walls of a case and a piston. The device includes a piston assembly having an outer piston structure with an inner piston structure therein. The inner piston structure is mounted on an eccentric on a crank shaft, the rotation of which causes nutating movement of the inner piston structure and a reciprocal linear movement of the outer piston structure. First sealing elements are mounted on the outer piston structure to provide sealing for the chambers having the outer piston structure forming part of the chambers, and second sealing elements are mounted on the ported faces of the inner piston structure to provide sealing for the chambers having the inner piston structure forming part of the chambers. Each sealing element includes one portion received in grooves in the piston structures and another portion with a plurality of spaced raised sections which engage the case walls.

Abstract: A power tool, particularly a hand-held power tool, has a striking mechanism with a striker transmitting impact energy to a tool, a drive operative for actuating the striker through an air cushion, and a heat insulating element which is associated with the striker and insulates the same from heat generated in the air cushion during the operation of the power tool. The heat insulating element may simultaneously be formed as a mechanical buffer.

Abstract: A hydraulically actuated brake fitted with a device to prevent an excessive rise in the temperature of the hydraulic fluid comprises an actuating piston in the form of a hollow body or cup within which is disposed an insulating core. The core has an outer face which engages the respective friction pad, and is engaged by a press fit within the cup by engagement means which leave an air gap between the core and the cup. The press fit engagement is thereby facilitated and heat transfer between the piston and the hydraulic fluid contained in the actuating chamber is reduced, thereby protecting the hydraulic fluid from an excessive rise in temperature during braking.

Abstract: In a radial piston machine, there is provided an outer stator and an inner rotor rotatable on a control pintle provided with supply and discharge channels. The rotor contains at least one radial bore in which is slidable a spherical piston comprising an outer ball and an inner cylindrical sleeve. The radially inward end of the sleeve, which end is adapted to be acted upon by the outlet pressure of the machine, includes a sealing lip which, during operation, in particular at higher pressures, expands circumferentially and, under certain circumstances, moves in sealing abutment with the inner wall of the radial bore.

Abstract: An engine piston is formed with a top crown surface and a top ring groove. An upper annular land surface is defined between the top ring groove and the edge of the top crown surface. The upper annular land surface and the side walls of the top ring groove are defined by a part of the piston which is formed of a matrix metal reinforced with inorganic fibers. The proportion of the inorganic fibers by volume in the reinforced part of the piston may optionally be approximately between 2% and 10%.

Abstract: A piston for a cylinder device which is formed of fiber glass strengthened resinous material and includes a concave portion, where a plug may remain, formed on an end thereof. The piston is engageable with a push rod and in particular an end surface of the push rod. The concave portion may be formed on approximately the center portion of the end concave surface of the piston and may be of circular configuration. Correspondingly, the concave portion may be formed on a flat surface of the end surface of the piston.

Abstract: A piston for a swash plate type compressor is disclosed in which a plurality of similar pistons are reciprocated to provide a compressing operation by means of a swash plate which is mounted on the drive shaft and rotated in the compressor cylinder. The piston comprises a piston main body or blank made of aluminium or aluminium alloy, and a coating layer applied to the overall surface of the piston blank except central portions of both outer end faces of the blank, said coating layer being of ethylene fluoride or a copolymer of ethylene fluoride and a vinyl compound, the heat conductivity of which is lower than that of the piston blank.

Abstract: A filled piston (10) has a tube (19) extending axially through the core (13) of filler material. The tube (19) provides the passage (23) through which hydraulic fluid passes to lubricate the bearing surfaces of components associated with the piston (10). This eliminates the problem of the hydraulic fluid eroding the filler material and thus the need for visual inspection of the passage through the piston.

Abstract: A master cylinder includes a housing (24) forming a bore (26) for receiving a first piston (38) and a second piston (40). Each piston is movable during braking to generate fluid pressure within a first pressure chamber (54) and a second pressure chamber (58), respectively. The first piston (38) is made from a stamping to define a uniform thin wall therefor. The stamped piston (38) forms a longitudinal body (84) movable relative to a fixed lip seal (32) and a base (86) defining a pocket (88) for receiving an input member (22).

Abstract: The spherical piston pump comprises an outer stator and an inner rotor rotatable on a control pintle provided with supply and discharge channels. The rotor contains at least one radial bore in which is slidable a spherical piston including an outer ball, a cylindrical sleeve and an inner ball. The outer ball, sleeve and inner ball are not fastened to one another and can be replaced independently of each other. Annular sliding members made of low-friction and sound-damping material can be integrated into the ends of the sleeve, each of the sliding members being in line contact with the associated one of the two balls. The construction provides good volumetric efficiency even at high pressure and an improved overall efficiency of the pump.

Abstract: A piston for a precision dosing instrument includes a cylindrical core which may be made of glass, ceramic or metal, and a precision ground sleeve of polytetrafluorethylene disposed over the core. One end of the sleeve is closed while the core is open at both ends but the openings may have different diameters.

Abstract: A fiber-reinforced piston for internal combustion engines, comprising a molded body of inorganic fiber forming a top land and a ring region of the piston. The molded body has a content of granulated fiber having larger particles of a particle diameter less than 100 mesh in an amount of not more than 10 weight percent with respect to the total amount of fiber used, and a light alloy matrix fills and is combined with the molded body of inorganic fiber.

Abstract: Apparatus for generating linear motion comprises a body on one end of which is mounted a cylinder. A piston in the cylinder is joined to an actuating beam extending into the body. The actuating beam has moving surfaces that cooperate with fixed surfaces in the body to define a linear bearing. Fluid under pressure is introduced through a duct in the body to a port in the fixed surface of the linear bearing. It enters the space in the cylinder above the piston via a port in a moving surface of the actuating beam which leads to a duct in the actuating beam that opens through the crown of the piston. A resilient sealing member between the fixed and moving surface of the linear bearing maintains fluid-tight communication between the fixed and movable part over their range of relative movement. The actuating beam may carry a rack that drives a pinion through ninety degrees as the piston travels, and two opposed cylinders may be provided to give a reciprocatory movement, or a spring return may be provided.

Abstract: A motor fuel feed pump with a tappet operated piston or membrane wherein the tappet is linearly guided and sealed in a housing segment which projects into the cylinder chamber of the pump on its suction side or its pressure side with inlet and outlet means positioned such that the motor fuel flows around and in direct contact with the projecting housing segment.

Abstract: An improved heat insulated piston assembly for an internal combustion engine and a method of assembly. The improved piston assembly includes a piston constructed of a sleeve having an interference fit about a heat insulated core. The core has a first end positioned flush with an end of the sleeve and has a second end located within the sleeve with a concave configured cavity formed therein. Mating in the concave configured cavity of the core is a connecting rod having a spherical ball shaped end. The spherical ball shaped end is securely held in the cavity by a retaining ring which attaches to the piston sleeve. The retaining ring allows for limited movement of the spherical ball shaped end of the connecting rod in the cavity while providing a means for returning the piston to its bottom position during the intake stroke.

Abstract: This invention relate to an improvement of the resinous brake piston of disk type, particularly the synthetic thermosetting resin piston of disk type whose opening end is thermally reinforced by simultaneous casting of the heat-resistant material, so as to prevent the crack in the opening end of the piston even when it comes into direct contact with the back metal of the friction pad of high temperature in the disk brake.

Abstract: An improved device is disclosed for connecting a plunger to a connecting rod of the type having a crosshead connected to the connecting rod, the crosshead having a coupling element with a flange and a coupling nut mounted to the flange. The coupling element is provided with a centering bore and a thrust plate is mounted to the coupling element. The thrust plate has a first side with a centering stud extended into the centering bore and an annular shoulder surrounding the centering stud seated against the flange. The thrust plate has a recess on a second side opposite the first side for receivingly centering an end of the plunger. A clamping assembly for clamping the coupling element includes a collar threadably engaged to the coupling nut.

Abstract: A sealing mechanism positioned between a movable piston wall and stationary cylinder wall concentric therewith. The sealing mechanism includes a circumferential groove formed in one of the concentric walls, and an O-ring positioned in the circumferential groove, the O-ring having a diameter less than the axial length of the groove and being compressed between a pair of opposing surfaces, a first surface formed integrally on the floor of the circumferential groove and a second surface formed integrally on one of the concentric walls. At least one of the pair of opposing surfaces has at least one upstanding serration for engaging the O-ring and forcing the O-ring to rotate when it moves from side to side in the circumferential groove.

Abstract: A ceramic cap is attached to a metal piston by means of intermeshing radial flanges. A spring forces the flanges into contact with one another along an annular surface area. Spaces between the flanges allow for movement between the metal and ceramic parts to accommodate differential thermal expansion, while at the same time permitting secure contact between metal and ceramic.

Abstract: An improved disc brake plastic piston is described which has a metallic cap or face which provides a means of attaching a brake shoe or a brake shoe assembly, or provides a dust boot groove, or, in a most preferred mode, the metallic cap component provides both a brake shoe retaining means and a dust boot groove.The piston is comprised of a cylindrical plastic body having an open end and a closed end. At least one ring bead can extend from the wall of the piston body contiguous to, or near, the open end. The bead or beads are suitably ejector beads utilized in the molding operation. A metallic cap extends over the end wall of the open end of the cylindrical body and is secured to the body by being snap fit or clamped over the ring bead. The cap is adapted to receive and hold a brake shoe clip, or provide a dust boot groove, and, in a most preferred embodiment, provides both a brake shoe retaining means and a dust boot groove.

Abstract: A vacuum actuated type booster device for assisting master cylinder of automobile braking system. The device has a booster shell, a booster piston reciprocatably received by the booster shell, a diaphragm connected at the inner peripheral portion thereof to the rear side of a disc portion of the booster piston and at the outer peripheral portion thereof to the peripheral wall of the booster shell, a first and a second working chambers defined in the booster shell by the booster piston and diaphragm, a vacuum source with which the first and the second working chambers are normally communicated and an input rod slidably mounted in the booster piston. The second working chamber solely is brought into communication with the atmosphere as the input rod is moved forwardly so that the booster piston is driven forwardly by the pressure differential between the first and the second working chambers.

Abstract: In a cylinder piston device, a piston unit is fixed to a piston rod member within a cavity defined by a cylinder member. The piston unit is provided with a piston ring supporting face, which is directed substantially in a radially outward direction towards the inner circumferential surface of the cylinder member. A piston ring member with a radially inner circumferential face and a radially outer circumferential face is supported by its radially inner circumferential face on said piston ring supporting face and engages by its radially outer circumferential face the inner circumferential surface of the cylinder member. The piston ring member is provided with at least one radially inward directed projection extending in the radially inward direction beyond the radially inner circumferential face, the projection axially engaging a securing face of the piston unit, and the securing face extending radially inward of the piston ring supporting face.